Pharos University Computer Skills & Programming Concepts I Lectures 12 PDF

Computer Skills & Programming Concepts I UEC01 – PCD104 – PCC104 – HGCP101 Lectures 12 Course Coordinator: Assoc. Prof. Mohamed Ismail Badawi 1  3 PUA – Computer Center – UEC01  Compu...

Computer Skills & Programming Concepts I UEC01 – PCD104 – PCC104 – HGCP101 Lectures 12 Course Coordinator: Assoc. Prof. Mohamed Ismail Badawi 1  3 PUA – Computer Center – UEC01  Computer Skills & Programming Concepts I UEC01 – PCD104 – PCC104 – HGCP101 IV. Communication and Internet Technologies Lectures 12 Course Coordinator: Assoc. Prof. Mohamed Ismail Badawi PUA – Computer Center – UEC01 Course Coordinator: Assoc. Prof. Mohamed Ismail Badawi Instructors: ▪Eng. Mohamed Ahmed Taha ▪Eng. Maher Habashy ▪Eng. Angy Saleh ▪Eng. Yasser Abd El Aziz ▪Eng. Reham Refaat ▪Eng. Nehal Essam 5 PUA – Computer Center – UEC01 This Lecture Covers: ❖What is a Network? ❖Network Characteristics: Topologies, Architectures & types ❖Data transmission Characteristics. ❖Networking Hardware. ❖Communications protocols ❖The Internet and the World Wide Web ❖The Internet Community ❖The Internet Access ❖Searching the Internet ❖The Internet Services 6 PUA – Computer Center – UEC01 Course Objectives ❖Define a computer network and its purpose. ❖Describe several uses for networks. ❖Understand the various characteristics of a network, such as topology, architecture, and size. ❖Understand characteristics about data and how it travels over a network. ❖Name specific types of wired and wireless networking media and explain how they transmit data. ❖Identify the most common communications protocols and networking standards used with networks today. ❖List several types of networking hardware and explain the purpose of each. 7 PUA – Computer Center – UEC01 Course Objectives Cont’d ❖Identify the various types of individuals, companies, and organizations involved in the Internet community and explain their purposes. ❖Describe device and connection options for connecting to the Internet, as well as some considerations to keep in mind when selecting an ISP. ❖List several ways to communicate over the Internet, in addition to e-mail. ❖List several useful activities that can be performed via the Web like browsing and searching the World Wide Web. 8 PUA – Computer Center – UEC01 What Is a Network?  Network is a connected system of objects or people  Computer network is a collection of computers and other hardware devices connected together so users can share hardware, software, and data, and electronically communicate.  Computer networks are converging with telephone and other communications networks. 9 PUA – Computer Center – UEC01 Network Characteristics  Wired vs. Wireless Networks  Network Topologies  Network Architectures  Network Size and Coverage Area 10 PUA – Computer Center – UEC01 Network Characteristics cont’d  Wired vs. Wireless Networks  Wired is a network in which computers and other devices are physically connected to the network with cables.  Wireless is a network in which computers and other devices are connected to the network without physical cables.  Data is typically sent via radio waves. 11 PUA – Computer Center – UEC01 Network Characteristics cont’d  Network Topologies indicate how the devices in the network are arranged.  Star Networks  All networked devices connect to a central device/server  If the central device fails, the network cannot work  Bus Network  Uses a central cable to which all network devices connect  Mesh Network  Multiple connections among the devices on the network so that messages can take any of several possible paths 12 PUA – Computer Center – UEC01 Basic Network Topologies 13 PUA – Computer Center – UEC01  Network Characteristics cont’d  Network Architectures  Client-Server Networks  Client: Computer or other device on the network that requests and utilizes network resources  Server: Computer dedicated to processing client requests often has several hard drives, fastest printer. 14 PUA – Computer Center – UEC01  Network Characteristics cont’d  Network Architectures cont’d  Peer-to-Peer (P2P) Networks  Central server is not used, Content is exchanged over the Internet directly between users  All computers on the network work at the same functional level  Users have direct access to the computers and devices attached to the network  Less complicated and less expensive to implement than client-server networks 15 PUA – Computer Center – UEC01  Network Characteristics cont’d  Network Size and Coverage Area  Personal Area Networks (PANs): Connect an individual’s personal devices, Devices must be physically located close together.  Local Area Networks (LANs): Connect devices located in a small geographic area.  Metropolitan Area Networks (MANs): Cover a metropolitan area such as a city or county.  Wide Area Networks (WANs): Two or more LANs connected together, Cover a large geographic area. 16 PUA – Computer Center – UEC01 Network Types PAN LAN 17 PUA – Computer Center – UEC01  Data Transmission Characteristics  Bandwidth is the amount of data that can be transferred over a communication link in a given period of time, Measured in bits per second (bps), Kbps (thousands), Mbps (millions ), or GFbps (billions).  Analog vs. Digital Signals  Data represented by two discrete states 0s and 1s (Digital signal)  Conventional telephone systems use analog signals that represent data with continuous waves. 18 PUA – Computer Center – UEC01 Data Transmission Characteristics cont’d  Link Transmission Type:  Simplex Transmission  Data travels in a single direction only  Example: television broadcasting  Half-Duplex Transmission  Data travels in either direction but only one way at a time  Example: bank teller sends data about a deposit; after data received, a confirmation returns  Full-Duplex Transmission  Data travels in both directions at the same time  Example: a conversation  Typically used for high-speed data communication 19 PUA – Computer Center – UEC01  Networking Media  Wired Networking Media  Twisted-Pair Cable  Pairs of insulated wires twisted together  Used for telephone and network connections (LANs)  Coaxial Cable  Thick center wire surrounded by insulation  Used for computer networks and cable television delivery  Fiber-Optic Cable  Utilizes hundreds of thin transparent clear glass or plastic fibers over which lasers transmit data as light  Used for high-speed communications  Wireless Networking Media  Data is sent through the airwaves using radio signals 20 PUA – Computer Center – UEC01 Networking Media cont’d 21 PUA – Computer Center – UEC01  Networking Hardware  Network Adapter: used to connect a computer to a network, also called network interface card (NIC) as an expansion card.  Modem: device that enables a computer to Communicate over analog networking media.  Switch: Central device that connects devices in a wired network but only sends data to the intended recipient.  Hub: Similar but sends data to all recipients.  Router: Connects multiple networks (LANs, WANs, and the Internet), passes data to intended recipient only and routes traffic over the Network(Packets Switching). 22 PUA – Computer Center – UEC01 End of Lecture 12